Machine for cutting involute spur-gears.



H. PERROT.

MACHINE FOR CUTTING INVOLUTB SPUR GMRS.

APPLICATION FILED 0012.9, 1911.

- Patented Feb. 24, 1914 a SHEETS-SHEET 1.

@www AMW/4%@ `H. PERROT. MACHINE FOR CUTTING INVOLUTE SPUR GEARS.

APPLIGATION FILED OGT.9, 1911.

Patented Feb. 24, 1914.

3 SHEETS-SHEBT 2.

H. PERROT.

MACHINE FOR CUTTING INVOLUTE SPUR'GBARS.

`.n1 G1Va. lvm 4. 2M IB .wm .a FE., dw., jan. l 6 t a. D.. L 1 9 1 9 m 0 0 m n y M Ff o I T A o I L P. P A

WfIT/VESSESI /ff/ HENRI ruimer, or "caminossz-SCOTLANDL MACHINE 'ron CT'iiNG `iiavontimii srUiifGEAnsf appiication fiieiioctobere, 1911i. siiliio. 653,715.

To all whom t may concern:

Zen of the Republic of Francefresiding in Cardross, Duinbartons'hire, Scotland, havef invented vcertain new and useful Improve.- l ments in Machines for'Cutting Involute" Spur-Gears, of 'whichthe following is a specification.

This invention relates to machines whichy of different sizes Without the need of siilostifl tutiiigv or `changing anyot the parts' of they machines and which comprise mechanisms speed as that ot' a pair of reciprocating tools that act on the tivo sides of a tooth at one time, and it consists in improvements having for their object an improved machine. for cutting' involute teeth on spur gcai'ingthe principle of Which Will be explained below.

Figui-esl to 7 inclusive a-re diagrammatic views illustrating certain principles involved in the present invention. The machine,i the,"v object of this invention and .constiuctedon the above-stated principles` is illustrated in Figs. 8 to 15 inclusive. FigV 8 is an elevation of one side of the machine. Fig. 9 is an elevation of the other side ofthemachine. Fig. 10 is a longitudinal section on theJ` lines M-M, N-N, Fig 8. Fig. 11 shows a detail of the traversing screw and tool carriage. Fig. 12 is a view of af portion ofthe carriage actuating mechanism partiallyin section on the .line PP, Fig. 8. Fig 13 is a partial plan view, showing portions of the mechanism illustratedin Fig. 12, and a` ;por` tion of the carriage. Fi 14 is a` sectional view on the line Q-Q, Fig. A10, of a portionv can gear with one another. It OCv (Fig. l)

is taken as the radius of the itch circle ofiv P sectorvof pitchradius R, it is necessary to that circle, the angle o: formedby that tangent and the line my, which is perpendicular to'OC, is the angle of Obliquity of actionand the vtangent AC is the locus'ofthe points of contact. ot' the Aiianli PQ constitutedby the involute of the hase circle of radius OA' and 90S? t i i It is'varied Without changing OA," that is to say Without changing the involute, then thepitch circle radi'usOC may bevariedxby t quantities as small asmay be desired. Sup-` i posing that OC in Fig.' 2=is the pitch radius Y are adapted to generate teeth on gearwheels i R Oft344 large toothed Sector meshing with a rack'TSimovable vertically byV means :of a

y screvnigiatfgthedaxle ofthe sector carries a `inion ora- .th"`th" "I that may be so adjusted that anysizegearl p lus T e tee Of Whlch are .blank to be cut may be rotated at thesame to be cutbythetoolsfg mounted on a` carrier adapted tothe. displaced horizontally by s ascrew 'L'. Supposing again, that the scren7 o ot the carrier and the screw that controls the rateatea renee,

- of tliestiaight MN ofttheiraclr, thenv i Be it known thatlI, HENRi'PERRonaVcitii rack are connected by` intermediate shafts.

and bevel Wheels,` with reducing gears'inten posed in such a manner.:..that"the vvelocity ratio of the carriage andof the rack TS equals the@ ratio jloetiiveen the radius of lthe *pinion the vradi-ills ffne'Sebwifftlieris If the tools have a movement parallel tothe breadth ofl the pinion `P to be cut `andthe carrier which carries them advances regularly according to the f displacement of the rack TS, then the sector andthe `pinion to he i cut having accordingly af correspondin angular displacement, the tooth of thepinion P will becut' with an involuteprofile. It,

for example, a Wheelfof` 51 teeth lwith a diametral pitch ``of325 (the'quotient ob.-Y`

tained by dividing the `diameter ofthe pitch circle by the number of teeth'iii the Wheel) has to be cut, and the pitch radius of sectorA fortexainple, that isto say with gears of 80, 21, 13 and 17teeth the desired` ratio can! `be attained. This` Shows that; for@ change the gears 'for cutting` pinion's of dif-- ferent radii 7'; a largek number of iiiterme,n

diategelars have been required for. cutting f r pinionsfor Whichfthe ratio Rhvaries con siderablyik l i y lheobject ofthe 4present invention is to permit, as Wfillrbe understood from `Wliatkfol- A" lowspthe'de-sired result to be ohtainedpthati; v to say to cut pinions `,for whichthesratio `,varies within'certain:limits,V without hav# ""ingto, change the 'intermediate gears .within r*.theS@i1-limits-y Y "-fI'thas heen?y previously seen in regard to l Fig. lthat if the angle of Obliquity of action c is modified withoutchanging OA', that'is t". ,varied-fas desired-.j n if aren, in 'Fig'. e al@v withoutfm'odifying the involute, OC' may be 'I toothed sector,of1rad ius R is'replaced by a cam a initheform" ofv an involute' as in Fig. 3 aiidfif'the verticallyv movable rackjof Fig. f2. isreplaeedby abar making-with OCan '.angle'cs .andA representingy a iiank of the rackV onwhich `the cam rests, the system of the inl`teianediate gears up to'i the rack of the tool lcarriageremaining the same, theny the angle qaenuy' naar@ mao therefore with am v.or lcan .bef varied,QOl modified andfconsetioir ofthe har b.

yduce a machinev of -cut gears tooth by tooth, ythetwo sidesofa tooth being cut;at one time. r` The cutting isfeifectedf by means ofv 30 'me was (Fig, .4) the aanks of which Correthe flanksy vo'ffitw) successive-teeth ofy the rackf 'i andthe flanks of a tooth of a lwheel engaged injthe space be considered, itis 'seen' the spendy withy the sides of .a space ybetween the -rackvteeth. 1f Aajsuccession of positions of flanks of thefteeth of the wheel' are consti-,f `tuted by a curve tangentto the flanks ofthe 'A Vtrack in allfpositions.,

They teeth ofthe wheel fte lhe vare rroughly formed beforehand as showninFig. 6,' where d represents a tooth .roughly formed, dt indicates a tooth in coursel of Y being cut and d2 shows. a completely cut tooth ;r the y, twov tools while .being traversed reciprocate. parallel-.to the axis of the pin- 'ionf as indicated in Fig. 7, the tools cut in one direction'of movement and return back y l .4 vwithout working or cutting.: While the cut- Y .ting is 'Y taking place in the direction kof -theddireetion ofarrow y and atl the same arrow-Ta1 the two tools are displaced'along timethe 'pinion being cutis subjected to s a'nrgangular*movementin `the directionof thekarrow 2 6). This goes on until. Y the c iuttingl of the'tooth is complete, `which thentakes the profile 'seen r in, broken lines atldl'Fig. 6. Fig.Vr 7' is'a'plan, toa smaller scale, ofthe varrangement in Fig. `6.

` The frame of the machine carries 4a slide celV VWay'. 1 for avear'riagelor` carrier 2 which Vvsupports the tool holder hereafter describedpthe axis ofv thek slide-1fisfperpen r 'dicula'rtothe axle lBlof theQpinion-ca-'rrier mandrel.

-fwedge piece 4'may be employed for adjusting purposes (Fig. 8).

The `("arriage 2 is shifted' by the screw 5 (see Fig. 11). The carriage has two limbs 21 which support a pair of nuts 22, in which the screw 5 engages. The interior of the carriage serves as a guide for the sliding fase orframe G which is reciprocated parallelfto the Uaxis of the mandrel. The displacement of that case is etlected by means of a pinion 7 carried by a spindle S and engaging with `a rack 9 disposed below the said case 6: -The tool carriers are arranged in the ease; A10 is a Wedge shape adjusting member for case 6. The tool carriers 11, v11 are disposed ona piece 12 pivoting on the axis 13 so as to permit the tool to free itself on its` return stroke, that is when it is' not operative. I

The necessary reoiprocative movement of the tools 14 isprocured.by-meansvof the pinion 7 carriedby the spindle 8. This spindle carries another pinion 26 which engages with a rack 2'( (Figs. 8 and 10) Whicliis correlated with a crank 28 of a crank disk 29. The crank 28 canbe displaced inaslot formed inl-'the disk 29 and be adjusted by a screw and nut;` the travel `of the rack 27 can be 'thusmodified and-accordingly the travel of the tool carrying frame 6, agreeably to the width' fof the pinion tobe cut. The disk 29 `receives its movement, as .shown partly in Fig. 12, from the pinion 30 loose on spindle 31, which pinion is operated from a spindle 32-byintermediate gearing which can be modified according to re uirements to vary the speed of the tools suc r as the gears 100, 101,102,103 and 104. VVhena tooth of the pinion iscut, thepinion is advanced so that a cutt-ingof a second tooth may be commeneed; during the angular displacement of the pinion thetool` must be prevented from operating.Y The arrest of `the tools in 'their rearpositionjis attained thus (see Fig. l2 and Fig. 13) the carriage 2 carries an arm 34 adapted to engage one or'other of two tappets or shoulders 35, 351 on a bar 36, 'which is formed with two heels 37, 371 adapted to contact with a finger 38 attached -to lever 39. Thislever 39 oscillates around 'a fixed axis 40 andi-terminates in a fork 41 the-branches of which carry a roller 42 adapted to travel in the circular groove of a toothed coupling 43 carried by a feathered ,key on the shaft 3l and adapted to engage carried, by the frame of the apparatus. The

lever 39 is integral with an arm 47ending vin a fork 48 adapted to act upon a-pin 49 attached to a nger Ofarranged toenter a notch formed on the periphery of a disk 51 fixed to the shaft 3l of the crank disk 29; the finger 50 enters the notch when the crank disk is in the dead point position. When a tooth to be cutis on the point of completion, the arm comes against the shoulder 35 of 'the bar 30, the heel 871 of that bar acts on the finger 38 and pushes the lever 39. In this movement, ihe roller 44 rolls on one of the oblique surfaces of the piece 45 and raises it and compresses the spring 46 when the roller 44 reaches the apexof the piece 45, the spring 4G reacts sharply and causes the roller 44 to pass to the other oblique face of 45 and the lever 39 rapidly pivoting around 40, the clutch 43 is thrown out of gear and consequently the pinion 30 ceases to turn 43. So long as the bar 30 has not displaced the arm 34, the arm 47 is raised and conse# quently the linger 50 is withdrawn from the slot in disk 51, and that can turn; but when the lever 39 is swung over the arm 47 descends and pushes the finger 50 into the notch 5l which stops the crank disk and at the same time there is a disengagement of the clutch member 43 by the lever 39. It is at this moment that the pinion P to be out -receives its angular displacementl and the tool carrying carriage .returns back to its initial 'position to reduce another tooth on the said inion. When the carriage approaches t ie 'end of the backward movement, the arm 84 acts on the shoulder 351 and the bar 30 moves the lever in a direction reverse to that previously. There'is then an en'- gagement of the clutch member' '43 with the controlling pinion 30 and at the same time the finger 50 disengages from the notch in disk 51 and frees the crank disk. The rotation of the screw in one or other direction according as the carriage is to advance toward the pinion lto be eut to effect the cutting of the tooth or to withdraw, is produced (see Fig. 10) by a worm 52 engaging with a pinion which imparts movement by inn terinediate gears 54, 541, 55, 551 which it is possible to modify according to the ratio Re way of the shaft 50 and bevel gears` 57, 571, the last carried by a shaft 58 operated by a shaft 59 by ineans of the bevel gears (30, G1. The shaft 59 is operated by the motor shaft 62 by the intermediate bevel gearing 03, 64 and shaft (35, the latter carrying two toothed wheels 00, 001. `Wheel 0G engages with wheel 07, and 001 actuates wheel 671 by means of gears 10G, 107 inounted'on a shaft 105. The object is to produce motion in opposite directions bv either wheels 467 or G71, the latter wheel being freely mounted on Vthe shaft 08. The gears ($0, (37 can be easily changed, the cover 09 of the casing which contains the gears being ren'iovable. The speed ratio can The worm 52 receives movement by bethus modified, and accordingly the speed gears 661, 671 and the intermediate gears 106, 107, by reason of their relative sizes, serve to effect the return of the tools with a Ispeed greater than that with which they operatively advance. The shaft 68 (Fig. 10) is connect-ed with one or other of the wheels 67, (S71 'by means of a -double clutch coupling 7l which is actuated by a forked lever 72 on which act the arms or stops 73 of a movable bar 74; a spring urged'double cone piece 75 has tliesaine function as the piece 45 previously described.. The bar 74 is displaced by the carriage which carries the ob lique bar described below. x The angular displacement, to which the pinion P is subjected while the tools-cut the flanks of a tooth, under conditions to be explained, is produced in the followinginanner: The pinion P is carried by a pin 76 (see Fig. 14) which is let into the end of shaft 3; this shaft carries a helicoidal wheel 77 which meshes with a. worm 78. The

worin 78 `forms part of the spacing mechanism carried by a frame 79 connected with a hollow shaft 80, but is not described, as it constitutes no part of the invention and may. be of any suitable character. The worm 78 is driven by means of suitable gearing 781 Fig. 8, actuating by means of 'the casing 99 a differential gear which also forms no part of the invention. This differential gear is itselfdriven by the worin 98 carried by thevsupport 79 Fig. 9, and capable of oscillating around the axis of `the pinion P. This worm 98 is connected with a bevelpinion 991 meshing with a second bevel pinion 992 carried by shaft which is subsequently referred to.- The shaft 80 carries keyed to it the nave of an arm o'r lever 8l having its edge fashioned to an'involute curve a (Fig. 10) the ontline of which is determined as already explained with reference to Fig. l.v The heavy -lever 8l reposes with its cam face a on an oblique plate or bar b which controls the progressive lowering of lever 81 and consequently the angular displacement, equally progressive, of pinion P, a displacement which is necessary to impart an involute profile to the flanks 'of a tooth of wheel P by means of Vtools with plane faces. The oblique bar Z is fixed by bolts on a support having a circular part 82 which can turn on an axle 83. The bolts 84 engage in a slot. 85 to allow the inclination of the bar b being modified and to fix the bar by means of nuts in the desired osition. ,The slot -85 may bel provided with a suitable graduated scale, whereby the inclination of the bar may be adjusted with precision. The axle 83 is supported by`-a carrier 80 (Figs. v9 and 10) which is displaced vertically on a guide of a frame 87 by means of a screw whieh'forms the prolongation of shaft and which is engaged by a nut 89 carried by the said carrier 86. This vertical shaft 59 is controlled as has been previously explained, and establishes the mechanical con'- nection between the mechanism for the transverse displacement of the tool carrying carriage and that which displaces vertically the inclined bar to canse by means of the arm 8l an angular displacement of the pinion I. ln the same manner as the return of the tool carriage is made more rapidly than the working advance, so the elevation of the oblique bar is accomplished morequickly than its descent which takes place during the period of the cutting of a tooth of the pinion. It may be borne in mind that the angular' displacement of the pinion P is effected by operating the hollow shaft 80 which carries it bymeans of the worm 78 and the helicoidal wheel 77. This mechanism and the shaft which carries the pinion I are supported by a carrier 90 which can be displaced with respect to the frame 87 agreeably to the diameter of the pinion. The tubular shaft 8O is integral with the supports 79 for the worm 78 and the other parts of the spacing mechanism.-

The power shaft 62 which is .driven by pulley G21 carries a pinion 92 (Fig. 9) connected by a chain with a pinion 93 whose shaft vtransmits movement by the bevel pinions 94.-, 9-11 and pinions 95', 951 tothe feathered shaft 96 which can move in the nave of the wheel 951 according tothe diameter of the uinion to be cut. This shaft 96 is held and guided by the support 97. As is understood, the support 79 can oscillate to some extent. around ythe axis of the shaft of the pinion to be cut, the tw'o bevel pinions 991` 992 remaining in mesh, while Athe shaft 9G is displaced longitudinally in its support. which can oscillate around the Vanis of pinion 95. (See Fig. 15.)

By this machine, which has two independent tools, a pitch circleofany radius may bev taken and a tooth having'any desired thickness and any angle of Obliquity .may be cut. This is particularly useful for the cutting of certain gears for automobiles` which'at times have profiles of a type out of the general run.V

The working of the machine takes place in the following manner: The tools being placed in their tool holders, and properly set.. the course of the tools is controlled as to length by adjusting the eccentricity of the pivot 28 (Figs. 8 and 12). If the thickness of the pinions to be cut is 30 millimeters, the course to be given to the tool is 40 nnn. in order to allow the tool to clear the pinion. The course of the tools is further regulated hy screwing or unscrewing the screw which forms a prolongation of the rack 27 (Fig. 8) so as to bring the stops in the travel of the tools at the entrance and exit ofthe teeth to be cut. The carriage 2 is then brought to one of its extreme positions by turning the screw 5 (the gearing 551, represented in Fig. 10 not being in place) by the aid of a handle which is fitted on the axle of the gear 551. The carrier 90, carrying the pinion to be cnt, is lowered by operating the wheel lV represented in Fig. 9, which wheel acts through the medium of conical pinions upon a screw engaging with the carrier 90. A graduated scale arranged along the sli-des of the carrier 90 is then consulted to determine the point at which one must stop in order to have the depth of tooth correspond to the model of the pinion to be cut. That done, the number of teeth which the gears 54, 54:1, 55 and 551 should have, and the inclination o: which should be given to the bar Z) is determined. 7' being thc original radius of the pinion to be cut., being th'e ratio of the reduction of the wheel and of the tangent screw 52, R being' the radius of the circumference of the base of a cam with an involute profile, we have:

' g r wheel 54 Wheel 541 1 R cos. @Fwhcel 55 whcel 551 5 The bar L being inclined by the angle a thus determined, and t-he wheels 54, 541, 55, 551, being putin place, the position of the shoulders 35, 351 (Figs. 12 and 13) is properly arranged, so that the tools may rstop at their rear position when the tooth is cut, and that they may be again set in movement when the following toot-h is ready to be cut. The stops 73 (Fig. 10) which control the mechanism for advancing and returning the carriage 2 areI then set. Care should be taken to have the return of the carriage 2 begin after the stopping of the tools in their rear position, and to again set in motion.

these tools by the shoulder 351 only when the return of the car 2 is completely ended. The spacing gears 77, 78I` 79, etc., governing the rotation of the pinion P (Figs. 8 and 14:) being putin place as well as the disengaging stop of the spacing apparatus, the gears controlling the movements of the cuttinfr of the tools as well as those giving the speed of advance, (that is to say, the thickness of the shaving to be taken off being carefully chosen) they can be set going. At this moment the carrier 8G (Fig. 10) is at. the bottom of its course and the carriage 2 is at the left; the carrier 8G ascends. the carriage 2 goes from left to right. and the tooth is cut. Then the cutting of the faces as regards two adjacent teeth is accomplished, the stop 34- (Figs' 12 and 13) comes to rest against the shoulder 35, the tools stop in their rear position. that, is to say, entirely disengaged from the pinion. The lower stop 73 (Fig. l0) clutches the mechanism controlling the descent of the carrier 86, the carrier descending quickly, while the carriage 2 is l displaced from right to left and whilethe dividing mechanism causes the pinion Vto be cut to revolvel by a length equal to the pitch for the cutting of the following faces.` The stop 34 acts upon the shoulder 351 and again sets the toolsin operation, at the same time that the upper stop brings about the clutching for the ascending vertical displacement of the carrier 86 and the cutting of twonew tooth faces opposite one another is effected. and soon..

Claims:

1. In a machine for cutting involute gears, the combination of a pinion -supporting mandrel, an arm having aninvolute cam, thereon, mounted concentrically with and adaptedto rotate saidjmandrel, an inclined support for said cam, a cutting tool having a feed transverse of said mandrel, and means for .moving said support proportional Vto the transverse feed of said cutting tool. u

2. In a mzfc'hine for cutting involut gears, the combination -of a pinionsupporting mandrel, an arm having an involute cam thereon, mounted. concentrically with and adapted to rotate said mandrel, an inclined support for saidcarn, a'cutting tool, means for feeding said cutting tool transversely of said mandrel; and gear connections betw'een said support and tool feeding-means for moving said support proportional to the transverse feed of said lcuttingtool. I

3. In a machine for cutting involute gears, the combination of a`pinion-supporting mandrel, an arm having an involute cam there-y on, mounted concentrically with and adapted to rotate said mandrel, an' inclined sup-v port fo; said cam, a cutting tool, mea-ns for feeding said cutting tool transversely of said mandrel, gear connections between said sup ort and tool feeding-means' for moving sai support proportional to the transverse feed of said cutting tool, said inclined support being adjustable, wherebythe machine may be adjusted for cutting. gears of different diameters without changing the ratio of movement between said support and tool feeding means.

4. In .a machine for cutting involute gears, the combination of a pinion-supporting mandrel, an arm havinganinvolute cam thereon, mounted ,concentrically with and adapted to rotate said mandrel, an inclined su port for said cam, a cutting tool having a eed transverse of said mandrel, and means for moving said support proportional to the transverse feed of said cutting tool, said inclined support being adjustable, whereby the machine, may be adjusted for cutting gears of different diameters-without changing the ratio of movement between said support and tool feeding means.

5. In a machine for cutting involute gears, the combination of a pinion-supporting mandrel, an arm having an involute cam thereon, Vmounted concentrically with 'and support for said cam, a Vcutting tool, a tool lcarrier havingfa feed transversely of vsaid mandrel, andintermediate gea-ring between said tool carrierY and inclined support, lsaid inclined supportbeing adjustable whereby -the machine 'may be adjusted for cutting ing the ratio ofmovementbetween said support andltool carrier..`

j 6.. In a machine for cutting involute gears, the combination of a'pinion-supporting mandrel, an arm having an involute cam thereon, mounted concentrically with and adapted to rotate said mandrel, an inclined support for said cam, a cutting tool, a tool carrier having a-feed transversely of said mandrel, means for moving said cutting tool in said carrier longitudinally of said mandrel, and intermediategearing between said machine may be a justed fon cuttinggears of ldifferent diameters without changing the ratio ofmovement between said support and tool carrier. 5

gears, the combination of a pinion-support- ;-ing mandr'el, an arm having an involute cam thereon-, mounted concentrically with and adapted to rotate said mandrel, an inclined support for said cam, a cutting tool, a tool carrier having a feedV transversely of said mandrel, means for moving said cutting tool in saidcarrier longitudinally of said mann'a-l movement of said cutting. tool, and intermediate caring between said tool carrier 4he adjusted'for cutting gears of different movement` between said support and tool carrier. v n

8. In\a machine for cuttlngmvolute gears, the` combination of a pinion-supporting mandrel, `-an arm having an involute cam thereon, mounted concentrically -with and support for said cam, a cutting tool, a tool carrier having a feed mandrel, means for moving said tool carrier transversely with a movement away from the pinion to be "cut of greater rapidity than toward the pinion to be cut, and intermediate gearing between said tool carrier and clined support, said inclined support being adjustable whereby the machine may be adjusted for cutting gears of different diameters without-changing the ratio of movement between said 4support and tool carrier.

the combination of a, pinion-supporting manadapted-to rotate said mandrel, an inclined" gears ofdifferent diameters without chang 7. In a machine for' 'cutting involute.

.diameters without changing the ratio of j l'iio transversely ofv saidsol tool carrier and inclined' support, said in-v clined support beino' adjustable whereby the asV drel and means for adjusting thelongitudiand incline support, .said inclined support being adjustable whereby the'machine may adapted to rotate said mandrel, an inclined j' 9. In a machine for cutting involute gears,

drel, an arm vhaving anfinvolute cam thereon,

f mounted coneentrically with and adapted to vvrotate said mandrel', an inclined support for saidcam, a cutting tool, al tool carrier hava ing a Afeed transversely of saidmandrel, and

intermediate gearing between said tool carrier'and inclined support, said inclined support being adjustable Vwhereby the machine may-beadjusted forcutting gears of diiierent diameters without changing the ratio of movement between said support and -tool carrier, and said mandrel having an .adjustablesupport whereby it may be adjusted forl pinions of different diameters.

10.y `In a machine for cutting involute gears, the combination of a pinion-supporting mandrel, an arm having an involute cam thereon,v mounted concentrically with and adapted to rotate said mandrel, an inclined support Vfor said-cam, a cutting tool, a tool carrier having a feed transversely of said mandrel, and intermediate gearing` between Y' said tool carrier and inclined siipport, said Yso intermediate gearing having achange-speed device whereby .the ratio of vmovement between said'support'and tool carrier may be changedforeutting gears of different diameters, and said inclined support being adjustable whereby the Lmachine may be adjusted for cutting gears of Ydiferentf'diameters intermediate the diameters whichV the machine may bezadjusted for by said change speeddevice; Y 11. In a machine foreut-ting involute gears, the combination of a pinion-supporting mandrel, an arm havingan involute cam thereon, mounted concentri'cally with and adapted torotate said mandrel, an inelined support for said cam,`a cutting tool, a'tool carrierl having a feed transversely of said mandrel, means for moving said cutting'tool in said carrier longitudinally of said mandrel` and means for automatically stopping said means for moving said cutting tool after the tool has completed cuttingy a tooth, and intermediate gearing between said tool carrier'and inclined sup? Aintermediate gearing comprising a -worm shaft engaging said inclined support carrier, said inclined support being adjustable whereby'7 the machine may be adjusted for cutting gears of different diameters without changing the ratio of movement between said support and tool carrier. In witness whereof, I have hereunto signed my name in the presence of two subscribingiwitnesses.

HENRI PERROT. Witnesses J. W. R. TEVNNANT, Gro. IVICCORMACIL 

